This invention relates to improved devices for lowering a person, persons or other load from one level to another, as for instance in escaping from an upper floor of a building during a fire or other emergency. Certain features of the invention have been shown in Disclosure Document No. 031598, filed in the U.S. Patent Office on May 6, 1974.
Various emergency escape devices have been proposed in the past of a type utilizing a unit which is adapted to support an escaping person or other load, and which is slidable downwardly along a flexible line at a controlled rate in a manner gradually lowering the person to a desired level. For example, such devices have been shown in U.S. Pat. Nos. 191,115, 207,856, 210,928, 283,702, 289,163, 311,039, and 504,868. In these devices, the flexible line in passing through or past the lowerable unit, is required to follow a circuitous path, in a manner introducing a substantial amount of friction between the line and the unit, and thereby resisting downward movement of the unit sufficiently to assure its descent at a safe speed. The circuitous path in some cases has been formed and defined by a coiled tube. For regulating the rate of descent, it has been proposed to provide a clamping device at the lower end of the circuitous path acting to resist movement of the line through that device and thereby vary the friction between the line and the tube or other structure defining the circuitous path.